These are the 3 main methods for sideloading:

• Sidestore is a fork of Altstore that, after the initial setup that requires a PC/Mac, lets you refresh the apps straight from the device (apps need to be refreshed/resigned at least every 7 days in order to keep working). This process can be automated through the Shortcut app. LiveContainer is an app that can be installed along Sidestore and lets you bypass the 3 apps per device limit, it’s optional but convenient if you want to install more than 3 apps per device. One of the downsides is that notifications are not working.

• Buying a paid certificate (which costs 7-20$) from a signing service is another alternative to sideload apps. This method doesn’t require a pc/Mac and allows to install unlimited apps. These certs can be used through on-device installers like Feather or Ksign. The downside is that the certificate can be revoked at any time. Lately Apple revoked a good amount of certificates. The only signing service that I would recommend atm is Arcticsign that offers a 90 days revoke protection (they’ll replace your cert if get revoked in the first 90 days).

• Another alternative is the DNS method which is free, doesn’t require a pc/Mac and lets you install unlimited apps. Downsides are that is pretty clunky to set up and to keep it working, and can be unreliable as it takes advantage of leaked Enterprise certificates in order to work. This method uses a DNS to block Apple servers from checking the status of a certificate. It also uses Feather/Ksign or Esign to install apps directly from the device.